Explanation:
Better known as
Hind's Crimson
Star, R Leporis is a rare star in planet Earth's night sky.
It's also a shocking shade of red.
The star's discoverer,
19th century English astronomer
John Russell
Hind, reported that it appeared
in a telescope "... like a drop of blood on a black field."
Located
1,360 light-years away in the
constellation
Lepus the star is a Mira-type variable,
changing its brightness over a period of about 14 months.
R Leporis is now recognized as
a carbon star,
a very cool and highly evolved
red giant
with an extreme abundance of carbon.
Extra carbon in carbon stars is created by
helium
fusion near the dying stellar core and dredged up into the
stars' outer layers.
The dredge-up results in an overabundance of simple carbon molecules,
like CO, CH, CN, and C2.
While it's true
that cool stars radiate most of their energy in
red and infrared light, the carbon molecules
strongly absorb what little blue light is left and give
carbon stars an exceptionally deep red color.
R Leporis is losing its carbon-rich atmosphere into the surrounding
interstellar material through a strong stellar wind though,
and could be near the transition to a
planetary nebula.
Oh, and Happy Halloween from the folks at APOD.